Warning signs of a bad gear box and ball joints

I'm guessing you mean the steering gear box, not the transmission. They can leak power steering fluid but they are more likely to develop play that causes steering wander and the need for constant steering correction. That isn't real common on your model.

Ball joints can cause a clunking over bumps or when turning, and if they get tight they can creak and squeak. Those should never be ignored. Most commonly they develop play, and when bad enough they will separate leading to loss of control and a crash. That is much more common on Ford products. To find the play they have to be inspected. You can have that done at a tire and alignment shop. The procedures vary by model. The looseness makes it impossible to keep the wheels in alignment so excessive tire wear and reduced handling result.